怎么回事呢？怎么会有错误呢

#include<stdio.h>

main()
{
    int age(int n);
    printf("NO.5 age:%d\n",age(5));
    return 0;
}


int age(int n);
{
    int c;
    if(n==1)
            c=10;
    else
        c=age(n-1)+2;
    return c;
}

编译显示错误：D:\2.c(12) : error C2449: found '{' at file scope (missing function header?)
D:\2.c(19) : error C2059: syntax error : '}'
Error executing cl.exe.